1. Field of the Invention
The present invention relates to a table sliding apparatus for slidingly drives a table carrying a work thereon for machining such as cutting or dicing a piece of metal, semiconductor into small strips or the like.
2. Description of the Prior Art
Conventional table sliding apparatus for slidingly drives a table carrying a work for machining is illustrated referring to FIG. 1, FIG. 2 and FIG. 3, which show an exemplary conventional apparatus for dicing by means of a diamond disk blade.
FIG. 1 illustrates fundamental principle of dicing or cutting a work by using a diamond disk blade 3, wherein the work 2, such as metal piece or semiconductor piece 2 is fixed on a sliding table 1 by a suitable bond, for example a wax inbetween. Then while the table 1 is put at a resting position at the left above as shown by chain lines in the FIGURE, the height of axis and position on the table of the disk blade 2 is adjusted so as to form a desired depth of the diced groove 4 at a desired position on the work piece 2. Then, the diamond disk blade 3 is rotated by a motor 5, and the table 1 is slid to the right lower side of the FIGURE, so that the work 2 is diced and groove 4 is formed to have a desired depth. When it is intended to cut the work 2 into strips, the height of axis of the disk blade 3 is adjusted in a manner that the groove 4 reaches or slightly exceeds the bottom of the work 2. In such case, usually a sheet of a relatively soft material, such as stucco or the like is inserted between the work 2 and the table 1. The sliding of the table 1 of the conventional apparatus is made by means of screw driving means illustrated in FIG. 2. The table 1 is formed in an inverted U shape and slidingly mounted on a guide block 6 by a suitable means. A driving screw rod 13 is rotatably held by a pair of bearings 7 and 8 fixed to brackets 16 and 17 which are integral to the guide block 6. The screw rod 13 is screw-engaging with a female screw threaded driven hole formed on or a nut 9 fixed on a moving bracket 15. The moving bracket 15 is fixed integral to the table 1. One end of the screw driving rod 13 is connected through a flexible joint 18 to an output shaft of a motor 20. When the motor is driven at a constant predetermined speed, the driving screw rod 13 rotates and drives the moving bracket 15. Therefore, the table 1 slides in the direction of the arrow "a" and makes the rotating disk blade 3 cut or dice the work 2.
Problem in such conventional construction is that, when the axis of the driving screw rod 13 is not straight, the driven screw hole 9 is vibrated radially of it, and therefore the table 1 receives pitching and yawing motions. Therefore, the work receives fluctuations of depth of the grooves 4 by the pitching motion and fluctuations of pitch between the grooves 4 by the yawing. Thus the accuracy of sizes of the works is spoiled by even a small deflection of the linearity of the driving screw rod. Furthermore, such pitchings and yawings of the table 1 causes the disk blade 3 to make a twisting motion F.sub.y or F'.sub.y, which, when larger than a certain limit, will breaks the rotating disk blade 3 and is very dangerous, and thereby the production yield of the works become very poor.